Typescript typings are wrong for onPicker* functions

[tbrent]

This issue is about onPickerConfirm, onPickerCancel, and onPickerSelect.

It looks like the typings here are wrong. InPickerTest, there are examples where the callbacks receive the index of the selected value. However, this is not reflected in the typescript typings. Instead, they show:

onPickerConfirm?(item: any[]): void
...
onPickerCancel?(item: any[]): void
...
onPickerSelect?(item: any[]): void

I believe the correct typings should be of the form onPickerConfirm?(item: any[], index?: number): void.